I too was a convent girl and can relate to the no eating in public rule, the hat and gloves on when in uniform outside (white gloves in summer, navy in winter). And absolutely no cavorting with boys while in school uniform, very unseemly. Our school careers advice, such as it was, largely amounted to warning us off becoming shop assistants or hairdressers, both considered very common
. Far more suitable were teaching or nursing. (Or better still, entering the convent!)
My mother had a thing about pierced ears, thought they were dreadfully common. As was wearing lots of makeup (particularly bright red lipstick), having bleached hair, going into public houses unaccompanied by a man. Oh, and I was never allowed to wear the rubber 'jelly' shoes because they were terribly common and people would think we couldn't afford proper shoes 